Method of cutting pipes



March 7, 1967 c. B. SMALL ETAL 3,307,760

METHOD OF CUTTING PIPES INVENTORS F17- E I Charles B-SmalL John, W MeeseHeinrich, 11- Frank March 7, 1967 C. B. SMALL ETAL METHOD OF CUTTINGPIPES Original Filed Nov. 22, 1963 2 Sheets-Sheet 2 INVENTORS Charles B.Small John W Mese Heinrich H. Frank 3,307,750 Patented Mar. 7,

' 3,307,760 METHOD OF CUTTING PIPES Charles B. Small, Elyria, John W.Meese, Avon, and Heinrich H. Frank, Elyria, Ohio, assignors to The RidgeTool Company, Elyria, Ohio, a corporation of Ohio ()riginal applicationNov. 22, 1963, Ser. No. 325,692, new Patent No. 3,221,962, dated Dec.7,1965. Divided and this application Nov. 9, 1965, Serz'No. 529,894

3 Claims. -(Cl. 225-1) This is a division ofapplication Serial No.325,692, filed November 22, 1963,-now Patent No. 3,221,962.

This invention relates to improvements in pipe cutters and a method ofcutting pipe. It is more particularly concernedwith an improvement inthe type of pipe cutter which employs a chain carrying a plurality ofcutting blades and which is wrapped around the pipe and tension appliedto the end for severing the pipe. It is of the general character as isshown by Patents 2,862,295, ofDecember 2, 1958; 2,793,433, of May 28,l957,and 1,510,256, of September 30, 1924. Cutters of this class areparticularly useful in cutting the more brittle pipes such as cast ironsoil pipe and clay pipe, and these are the principal types of pipes withwhich they are used.

' Heret-ofore it has been proposed to cut pipe by'the use of chain typecutters, of the above stated class, where tension was applied to theendsof thechain by a pair of handles similar to that used by boltcutters, as shown in Patent 2,793,433. It was also contemplated thathydraulic means be used for applying tension to the ends of the chainsuch as shown in Patent 2,862,295. The use of screw operated means forapplying the tension is shown in Patent 1,510,256.. When the bolt cuttertype of handles were used, the cutters were difficult to handle,particularly where the cutting was effected in a trench, because thesides of the trench interfered with the opera tion of the handles.Furthermore they were cumbersome and difiicult to handle, being largeand heavy. In addition, the operation required a great amount ofstrength on the part of the operator. The hydraulic means frequentlyrequired the use of a separate pump and connecting hoses whichcould leakand both of which required continuous maintenance. They also requiredsealing means for the hydraulic fluid, and the high pressure encounteredrequired continued maintenance. These were also more costly to produce.They were also difilcult to apply to the pipe being cut. Frequently itwas difiicult to find a place to mount the pump where it couldbe easy tooperate. It was also extremely slow in operation. cult to useparticularly on the less brittle types of materials.

The present invention contemplates a cutter where a chain bearing cutteris connected between the ends of a pair of relatively short scissorconnected levers, the other ends of which are moved by a screw means anda ratchet handle, to exert tension on the chain which is passed aroundthe article to be out. By this means a very simple mechanism is providedwhich is of small compass and light weight. The parts are so arrangedthat they cannot be contaminated and thus become inoperative. It can bequickly and easily applied to a pipe because the mechanism is not bulky.Because the mechanism is small and compact it is easily transported, andis particularly easy to apply to a pipe in places and in environmentswhere the other types of cutters cannot be used. It is substantiallyfree of maintenance problems. It can be operated with a minimum ofeffort because a large mechanical advantage is realized due to thecooperation of the levers, which provide a mechanical advantage inthemselves, with a screw and ratchet means for operating the levers.

The screw operated cutter was also diififrom the manner of itsoperation.

operating handle is required and .the movement ofthis handle is in aplane coincidental with the axis of the pipe, therefore there is nothingto hamper itsoperation since the movement of the handle during thecutting operation is along lines parallel to the longitudinal axis ofthe pipe and the sides of the trench do not-interfere with its movement.The pipe also acts as a' base'or'sec- 0nd lever. for absorbing theeffort applied to the device through the handle; therefore the handle,can be operated bytwo hands if desired. Due tothe mechanical advantagegained, however, less effort is required and greater force can beapplied and only one hand is needed to operate the same.

Another advantage of the above construction is realized In the priordevices the chain was merely tightened around the pipe and the cutterblades forced substantially radially inward of the pipe until theypenetrated the pipe far enough to cause the pipe to break. Such movementof the cutter Wheels as there was, other than radially, wascircumferentially of the pipe, and this movement was minimal. In thepresent invention, the movement of the ratchet handle longitudinally ofthe pipe causes a rocking of the cutter blades at the end of the scissorlevers and some rocking of the cutters on the adjacent links. Therocking is longitudinally of the pipe and diminishes in the cuttersprogressively around the pipe away from the lever ends. The aboverocking starts as soon as the worker starts to use the ratchet and isdue to the alternate to and fro movement, of the ratchet handle. Thismovement increases as the chain tightens and more etfort is required tomove the ratchet handle.

The result of the foregoing is that the contact of the blade with thepipe has another increment of force added to the radial force and thisforce is not present in any of the prior art. That is, as the blades arepressed in, they also partake of a pivotal transverse movement, whichcauses better penetration with less effort. In addition, as the bladespenetrate deeper into the pipe, there is a leverage applied by therocking movement of the cutter on the sides of the indentations on thepipe which causes the pipe parts to be forced apart in a longitudinaldirection. Thus the pipe is separated quicker and there is less chancethat the pipe will be crushed, as in the prior art which partake-slargely of a radial inward movement with a resultant irregular breakagearound its periphery, which is undesirable. In addition to the above,the longitudinal forces causing separation are also assisted by theparticular formation of the cutter blades.

Still other advantages of the invention, and the invention itself, willbecome more apparent from the following description .of an embodimentthereof, which description is illustrated by the accompanying drawingsand forms a part of thisspecification.

In the drawings:

FIG. 1 is a side elevational view of a pipe cutting tool, part of theend of the handle being broken away, and illustrating its manner ofengagement with a pipe;

FIG. 2 is a similar view at to FIG. 1, with the otally connectedtogether in scissor fashion intermediate their ends.

At the ends the levers are connected to a link chain, the pivots ofwhich have cutter wheels mounted thereon. The other end of the leversare engaged with a screw mechanism, which may be operated by a ratchet,to pull the ends of the levers together and cause the other ends toexert tension on the ends of the chain, which surrounds the pipe, tocause the pipe to be severed. During the ratcheting of the screwmechanism, the levers, together with the cutter blades, partake of atilting or rocking movement on the pipe. The pivot for the levers issuch that the parts beyond the pivot, where the force is applied, arelonger than the parts which are connected to the chain, thus realizing amechanical advantage.

More specifically, the device includes two pairs of levers and '11,which are generally of S shape. The pair of levers 10 have their upperends secured together in spaced relation by cylindrical bosses 12, whichextend from each side of a trunnion. At their lower opposite ends theyare secured by a hook link pin 14. Spaced from the lower ends they areconnected by a hinge pin 15. The pins extend beyondthe sides of thelevers and are locked in position by C rings 16, which are disposed ingrooves in the pins.

The other levers 11 are secured together in a like manner but lesswidely spaced since they are journalled on the pivot pin 15 between thelevers 10. The upper ends are engaged with an eye pivot pin 17 and thelower ends with a chain link pin 18. They are likewise secured in placeby C rings 16. Because of this arrangement each of the pairs oflevers 10and 11 move as a unit.

The cutter chain is of the link type and has cutter members carried byeach of the pins which connect the links together. Referring to FIGS. 1and 3, the first link of the chain is comprised of a pair of spaced sidelinks 20, the ends of which are journalled on the link pin 18 at thelower end of the lever 11, and the other ends being journalled on a linkpin 22 between the more Widely spaced side links 23 of the nextsucceeding link. Also journalled on the pins 18 and 22, between thelinks 20, are the cutter members, which in this instance take the formof cutter wheels 24. This arrangement continues throughout the length ofthe chain, each link pin having a corresponding cutter wheel.

As can best be seen from FIGS. 2 and 4, the link pins i 22 projectoutwardly beyond the sides of the links to "provide projections 22a,whereby the chain may be removably secured at any of the link pins 22 toa hook 3 coupling on the end of the other lever 10, while the endf-p'reviously described remains attached to the lever 11 at all times.

The purpose of enabling the chain to be attached at any point throughoutits length to the levers It), is to enable the cutter to be used withdifferent diameters of pipe. To this end, the ends of the levers 10 areprovided with hook means which enables the pins 22 to be hooked therein.

As best shown in FIGS. 3 and 4, the levers 10 are apertured near theirends and the pin 14 extends through these apertures, bridging the spacebetween the levers. The pin has a cutter wheel 24a rotatably journalledon the central part, which in this instance is provided with hubportionsextending laterally from each side. This prevents the pin 14from bending under load. It is flanked on each side by hook side links,that are right and left hand links, each being a mirror image of theother. They each comprise a pin engaging part 30, of a thickness toclose the space between thecutter wheel hub and the levers 10 androtatable on the pin 14. The inner ends of the side links toward thelever 10 are each provided with an extension 31. Near the end of theseextensions a pin 32 is secured which bridges the space between thelinks. The lever hinge pin 15 is provided with'a sleeve 15a, whichbridges the space between the levers v11. This sleeve has a centralcircumferential groove 15b, and a helical spring 33 has its endsconnected to the pin 32 with the body of the spring stretched to providetension thereon, and seated in the groove 15b surrounding the sleeve 15aand pin 15. The lever hinge pin 15 and sleeve 15a may also be one solidmember which would increase its rigidity and prevent shearing under loadsince the part 15a could extend into the levers 11. Since the hook linkis free to rotate on the pin 14, the force of the spring from the pivotpoint for the levers to the pin 32 always causes the links, in theirfree position, to project from the ends of the levers on a linecoincident with the axes of the pins 15, 32 and 14. This, as will laterbe seen, holds the" link in a position Where it is always readilyengaged with the chain projections 22a, and this facilitating assemblywith the pipe to be cut.

The bodies 30 of the hook links extend beyond the ends of the levers 10,and then extends laterally outward at 34 to provide a thickened portion.The inner walls of the thickened portion, the innermost surface of whichis coincident with the inner surface of the body 10, are formed withrecesses to provide hook shaped seats 35, which open vertically upwardand thus provide hooked ends 35a. The outwardly extending ends 22a ofone of the pins 22 may engage in these hook shaped sockets, as best seenfrom FIGS. 3 and 4. It will thus be seen that the hook seats arereinforced 'by the outer walls and can be subjected to extreme tensionwithout distortion.

The screw means for controlling the movement of the levers includes aneye 40 of an eye screw secured by the eye pin 17 between the levers 11and which has a shank 41 provided with left-hand threads 42. The threadsmay be of the Acme type and be either single, or multiple lead threads.In this instance, double lead threads are preferred. The shank 41 of theeye screw extends through the head 44 of a ratchet sleeve and is inthreaded engagement with internal matching threads 45 thereof. The headof the ratchet sleeve is provided with ratchet teeth 46. Adjacent thehead the ratchet sleeve is provided with a stern portion 47 of reduceddiameter, followed by an enlarged and elongated part 48 havingright-hand external threads which extend outwardly of the part 47. Thesethreads may also be of the Acme type and single or multiple threads;dual lead threads are preferred. The extreme end of the ratchet sleeveis provided with a smooth reduced portion 49, which may be substantiallythe same size as the part 47, or of a diameter equal to the rootdiameter of the threads 48 and has a cross pin 50 extending across thediameter and held in position by heading or staking the ends. Thethreads 45 extend to a point substantially opposite the beginning of thethreads 48 and is then followed by a smooth bore 51 which has an innerdiameter substantially the same as the root diameter of the threads 45.

The head 44 of the ratchet sleeve has a ratchet body 52 disposedthereon. The ratchet may be of conventional construction and includes anenlarged bore 53, which surrounds the teeth 46 on the head 44, and aninwardly extending flange 54 which rides on a shoulder on the ratchetsleeve head adjacent the sleeve which prevents it from coming off thehead. Further longitudinal movement of the ratchet body 52, relative tothe teeth, is prevented =by a washer 55 seated in the bore at the outerends of the teeth 46 and held in place by a spring retaining ring 56seated in a groove in the ratchet body. The ratchet head is counterboredat the outer end and a grease seal 57 is seated in the counterbore andheld in place by the washer 55. The seal engages with the shank 41 ofthe screw eye and prevents escape of lubricant through the end thereof.

The ratchet body has the usual ratchet pawl 60, having a stem 61 whichextends outwardly'through a boss 62.

A knob 63 is provided on the end of the stem, being held thereon by across pin 44. A coil spring 65 is provided with one end seated in theend of a bore in the boss and the other end engaging the pawl body tocause the pawl to be spring-pressed inwardly. The end of the boss isprovided with notches 66 into whichthe pin 64 may pass when the pawl isrotated to bring the pin 64 into alignment with'the notches. ,At thistime the end of the pawl 60 engages with the teeth 4.6,and beingwedge-shaped may be ,used to turn the ratchet sleeve with the usualratcheting action in either, direction,depending upon vthe position towhich the knob 63' is turned before allowing the pin 64 to pass into thenotches.

' Obviously swinging of the'ratchet handle 67 causes the ratchet sleeveto be turned."

As previously stated, the pair'f'of levers have their upper endsjournalled on apair of trunnion pins 12. The trunnion member comprises abody'7 0 having an internally threaded bore 71, which is in threadedengagement with theright-hand threads 4803? the ratchet sleeve. Thelefthand end of the *bodyis providedwith a counterbore in which'a greaseseal 72 is disposed and held in place by a cup retainer ring 73. Thegrease seal engages with the outersurface 47 of the ratchet sleeve andthe retainer ring extends toward the surface of the shaft slightly belowthe crests of the threads 48.

The body 70 has a reduced diameter portion 74 which is provided with aperipheral flange 75, spaced from the end.

v A knob or hand wheel is provided by which the ratchet sleeve may berotated independently of the ratchet to provide a ,quick adjustment ofthe device. The knob includes a head 76, having a skirt 77 which extendsto the left, over the stem 74 and flange 75 of the ratchet sleeve. Theskirt is provided with aninwardly extending portion which is formed toprovide a fia'ngef78, which rides on the portion 74. Adjacent theflange, the skirt has a counterbore for the reception of a greaseseal'79, which engages with the flange 7S and the surface'74 on theratchet member. The knob is held on theratchet member by a retainer ring80, seated in a groove in the skirt and extending opposite to the flange75p The head 76 of the knob is provided with a ratchet sleeve operatingmember which includes a body 85 pressed into an opening in the head andhaving a slotted stem 86 coaxial with the skirt extending into thesmooth bore 51 of the ratchet member. The slots 87 are sufficiently wideto enable the pin 50 on ratchet member to pass therein and engage withthe walls of the slot. The skirt 77 of the knob is knurled and, when theknob is rotated by hand, the stem 86 engages with the pin 50 and rotatesthe ratchet sleeve.

A lubricant fitting 90 is provided for supplying lubricant through thehead 85 to the interior of the device.

It will be apparent that when the ratchet sleeve is rotated, either bythe knob 76 or the ratchet, that the engagement of the threads 45 on thesleeve with the threads 4-2 on the eye screw, will cause the screw to bemoved to the right or left, depending on the direction of rotation ofthe sleeve. At the same time the engagement of the threads 48 on theoutside of the ratchet sleeve with internal threads 71 of the trunnionmember will cause that member to be moved to the left or right. Sincethe eye screw is connected to the lever 11, and the trunnion member tothe lever 10, the above movement will cause the ends of the levers to bemoved together or apart.

In operation, the knob 76 is first turned to cause the upper ends of thelevers to be moved apart. This is the position shown in FIGS. 1 and 3. Apin 11a carried by the lever 11, projects outwardlyon opposite sides,and when the levers are moved, the pin engages with the edges of thelever 10 and limits the opening thereof, thus preventing the screwmechanism parts from becoming disengaged with each other. The chain isthen passed by hand around the pipe to be cut, pulled as tightly aspossible and the ends of one of the link pins, closest to the hook link,placed into the hook seats. This is facilitated by the fact that thespring 33 engaged with the pin 32 holds the hook members in a positionoutward of that shown in FIG. 3.

Then the hand knob 76 is rotated in the other direction to bring theupper ends of the levers 10 and 11 toward each other, to quickly tightenthe chain around the pipe. This preliminary tightening can be effectedquickly and relatively easy, since the chain can be held in position byone hand and the knob rotated with the other hand.

After the slack is taken out of the chain, the knob 63 on the ratchet isturned to the proper position so that the pin 64- drops into the notches66 and the pawl engages with the teeth on the ratchet sleeve. is thenrotated by the handle to cause the upper ends of the levers 10 and 11 tobe pulled together, increasing the tension on the chain around the pipe.

The cutter members, which are illustrated as cutter wheels, have a novelformation; the extreme edges 24a of the wheels are provided by sidesthat have a total included angle of 60 and this is backed up by aportion 24b having sides that have an included angle of as best shown inFIG. 6. The height of the outer portion may be substantially the same asthe inner portion, although preferably it is less. As an example, for acutter Wheel having a diameter of 1.225 inches, the part 24a could be",-and base part 24b It is also pointed out that the extreme edge ispreferably not a sharp edge but one with a radius, which could be .007to .009 inch.

As the ratchet is rotated and the chain tightened, the sharper angledpart of the wheel readily penetrates the outer glass-like surface of thepipe. It will be appreciated that the effort to move the handle isopposed by the pipe itself which cannot readily tilt lengthwise,particularly when it is on the ground, in the bottom of a trench, or isapart of a string of pipes. It will also be appreciated that the effort.to move the handle increases as the chain is pulled tighter. of thehandle, the torque appliedto the ratchet sleeve causes a tilting of thelevers 1041, relative to the longitudinal center line of the pipe withthe cutter blades 24 and 24a, which are in the pipe engaging ends of thelevers, acting as a fulcrum. Thus, each time the ratchet handle isoperated to increase the tension on the chain, there is an inward radialmovement of the cutter wheels, along with a slight circumferentialmovement and a rocking movement of the blades at the ends of the levers.As the blades gradually penetrate the work, the rocking movement becomesmore effective and there is now a slight kerf which has been formed bythe cutter blade and as it is rocked the side edge of the kerf becomesthe fulcrum point and the extremity of the blades on the end of thelevers is pushing alternately with the rocking movement against theother side of the kerf, tending to push the two parts of the pipe apart.

As the tension is further increased, the sharper edge eventuallypenertates to its full depth, if the pipe does not break first, then thewider portion of the blade enters the kerf and provides a wedging actionwhich, along with the tilting action, is effective to eventuallyseparate the pipe.

The tilting action also assists the cutter to penetrate the pipe andthis is in addition to the radial action with a result that the pipe isseparated much sooner and with less pressure than where a radialpressure alone is used. Since less pressure is required, there is lessopportunity for the pipe to be crushed and the edges are cleaner andless jagged than with the other cutters. 7

Another advantage realized is that the pressure can be applied asgradually as desired and in time the operator is able to recognize theamount of pressure required to break the pipe and thus is not caught bysurprise when the pipe does break. In some instances he may operate thehandle to apply a certain amount of pressure and then rock the handleback and forth without actually increasing the pressure. This providesanother action in that the parts of the chain which are not being rockedhave the radial tension increased and decreased synchronously with therocking action and the lever action The ratchet sleeve Since the pull ison the outer end 68' 7 by the cutters at the ends of the levers 10-11.This causes the pipe to disintegrate in the kerf and assists in a cleanbreak.

When the pipe finally does break, the piece being broken off, if ithappens to be short, is not ejected violently away from the large pieceand thus does not fly away and strike other workmen.

The end of the handle 67 is provided with a grip 68. Spaced from the endis a flange 69 which prevents the hand from hitting the pipe. This isparticularly useful when the final break occurs and the chain passesthrough thepipe suddenly, relieving tension on the ratchet mechanism.

It will be seen that by this arrangement the compass of the tool is verysmall, thus it can be made relatively light in weight and this greatlyfacilitates handling, both on'the ground and in the trench. It isparticularly useful where it is desired to cut into a line which may beabove the ground, such as a vertically extending soil pipe. The handoperated knob, for preliminary tightening of the chain, facilitatesassembling the cutter with the pipesince the chain may be passed aroundthe pipe and hooked in the hook 35 and held in position with one handand the knob rotated with the other hand. This also enables the deviceto be easily attached to the pipe at the exact spot where the cut orbreak is to be made. After the pipe is broken, the levers may also bequickly moved to their original position.

Of particular importance is the fact that there are no handles whichhave interference with the sides of a trench and the device can beoperated in places Where a pair of handles could not be operated at all.Furthermore it should be realized'that the outside diameter of the pipesmay vary, due to irregularities or manufacturing tolerances, and thereare no handles which, at the start, are either so far apart that theycannot be operated, or so close together that they cannot be moved farenough without contacting with each other, to break the pipe.

A peculiarity of the present construction resides in the fact that theratchet handle is always opposite the pivot for the levers and midwaybetween the upper ends of the levers. Thus when the ratchet is operated,the. forces are applied to the ends of the levers in a bal- 8 ancedmanner and there is no tendency for one sideof the assembly to be tiltedmore than the other. This feature is particularly valuable in connectionavith the application of the intermittent longitudinal forces bythe cutter blade to the pipe, which assists in parting the pipe.

It has been found that the ratcheting action is such as to provideincreased tension to the chain in an intermittent manner. That each timethe ratchet is operated to increase the tension, the pressure of'thecutters on the pipe increases as the ratchet is being moved. Then, whenthe ratchet is moved backward, during the interval of the backwardmovement, the pressure ofthe wheels on the pipe decreases somewhat dueto their continued penetration of the pipe.

The device constructed as shown is substantially impervious to water,ice or mud and therefore cannot become clogged. Foreign material cannotget into the inside and cause wearing of the parts.

Having thus described our invention in the embodiment thereof, we areaware that numerous and extensive departures may be made therefromwithout departing from the spirit or scope of theinvention as defined bythe ap pended claims.

We claim:

1. The method of cutting pipe which comprises applying concentratedradi-al pressure around said pipe with a plurality of circumferentiallyspaced cutter means, and conc omittantly applying force to urge rockingmovement to at least one of said cutter means.

2. The method of claim 1, wherein the radial pressure and rockingpressure are progressively increased.

3. The method of claim 2, wherein the pressure increases are appliedintermittently.

References Cited by the Examiner UNITED STATES PATENTS 8/1960 Wheeler225-1 WILLIAM W. DYER, JR., Primary Examiner. J. M. MEISTER, Examiner.

1. THE METHOD OF CUTTING PIPE WHICH COMPRISES APPLYING CONCENTRATEDRADIAL PRESSURE AROUND SAID PIPE WITH A PLURALITY OF CIRCUMFERENTIALLYSPACED CUTTER MEANS, AND CONCOMITTANTLY APPLYING FORCE TO URGE ROCKINGMOVEMENT TO AT LEAST ONE OF SAID CUTTER MEANS.